Fix crash when `applybuffstack` is called before `applybuff`
Fix crash when `applybuffstack` is called before `applybuff`

hasseboulen/WoWAnalyzer,Juko8/WoWAnalyzer,hasseboulen/WoWAnalyzer,hasseboulen/WoWAnalyzer,enragednuke/WoWAnalyzer,anom0ly/WoWAnalyzer,ronaldpereira/WoWAnalyzer,fyruna/WoWAnalyzer,enragednuke/WoWAnalyzer,yajinni/WoWAnalyzer,mwwscott0/WoWAnalyzer,FaideWW/WoWAnalyzer,sMteX/WoWAnalyzer,anom0ly/WoWAnalyzer,sMteX/WoWAnalyzer,sMteX/WoWAnalyzer,ronaldpereira/WoWAnalyzer,WoWAnalyzer/WoWAnalyzer,yajinni/WoWAnalyzer,enragednuke/WoWAnalyzer,fyruna/WoWAnalyzer,FaideWW/WoWAnalyzer,anom0ly/WoWAnalyzer,fyruna/WoWAnalyzer,Juko8/WoWAnalyzer,yajinni/WoWAnalyzer,FaideWW/WoWAnalyzer,anom0ly/WoWAnalyzer,Juko8/WoWAnalyzer,WoWAnalyzer/WoWAnalyzer,yajinni/WoWAnalyzer,ronaldpereira/WoWAnalyzer,mwwscott0/WoWAnalyzer,WoWAnalyzer/WoWAnalyzer